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NHTSA defends new standard for truck trailer underride guards

Former agency chief says new regulation amounts to 'regulatory malpractice'

94% of trailers already meet the new standard, according to NHTSA. (Photo: Wabash National)

The National Highway Traffic Safety Administration is upgrading safety standards on rear underride protection on tractor trailers to help prevent crashes involving passenger vehicles, but safety advocates say the changes do not go far enough.

In a 107-page final rule made public on Thursday, NHTSA said it will adopt requirements similar to Canada’s standard for rear impact guards. Rear guards on truck trailers will be required to “provide sufficient strength and energy absorption to protect occupants of compact and subcompact passenger cars impacting the rear of trailers” at 35 mph (56 km/hour).

Rear underride crashes occur when a passenger vehicle strikes the back of a generally larger vehicle and the front end of the passenger vehicle slides under the rear end of the larger vehicle.

In extreme underride crashes involving tractor trailers, the passenger vehicle can underride the trailer to such an extent that the end of the trailer enters the passenger compartment of the colliding vehicle, severely injuring or killing occupants of the car. Underride guards mounted on the rear of trailers can prevent serious injuries and deaths resulting from underride crashes.


The final rule, which makes no substantive changes to the proposed rule that preceded it in December 2015, will improve protection in crashes in which a passenger car hits the center of the rear of the trailer, according to NHTSA, and in which 50% of the width of the passenger motor vehicle overlaps the rear of the trailer.

“NHTSA’s priority is the safety of everyone on our roads,” commented NHTSA Administrator Steven Cliff. “This new rule will improve protection for passengers and drivers of passenger vehicles while also meeting a critical mandate from Congress under the Bipartisan Infrastructure Law.”

Passenger protection technologies in vehicles striking trucks will be able to absorb enough of the crash forces from the impact to “reduce significantly” the risk of fatality and serious injury, according to the final rule.

Because an estimated 94% of applicable trailers already have compliant guards, according to NHTSA, the annual average incremental fleet cost of equipping the remaining applicable trailers with compliant rear impact guards is estimated to be $2.1 million in 2020 dollars. The added average weight of 48.9 pounds per vehicle that the guards add would result in an estimated annual fleet fuel cost of approximately $4.43 million and $5.59 million, discounted for inflation at 7% and 3%, respectively.


Advocates for Highway and Auto Safety (Advocates), which had sought much more stringent underride requirements, was “deeply disappointed” by NHTSA’s final rule, particularly after the agency’s data recently revealed that large truck fatalities are on the rise.

“Unfortunately, today’s action allows trucking companies to choose a less safe course of action at the expense of road user safety,” said Advocates President Cathy Chase on Thursday.

Joan Claybrook, a safety advocate and a former NHTSA administrator, said it would have been better had the agency not acted at all.

“This final rule…amounts to nothing less than regulatory malpractice,” Claybrook said. “Instead of improving protections to reduce underride fatalities and injuries, the agency has gone backward by issuing a rule that 94% of trailers already meet. As such, NHTSA has lowered the bar on public safety instead of ensuring it. This is an affront to the families of underride victims who have been working so hard to have the standard updated.”

In developing its rule, NHTSA had considered a standard in which rear impact guards withstand a 35 mph crash of a passenger vehicle into the rear of a trailer wherein only 30% of the width of the passenger vehicle overlaps the rear of the trailer.

The agency asserted however, that available data related to this standard — which would have required a modified rear guard and therefore more costly for the industry overall — do not show such a standard “would be reasonable, practicable, or appropriate” for vehicles subject to the regulations.

“Accordingly, NHTSA cannot conclude that a federal mandate for such a requirement for all trailers is warranted at this time.”

The rule is effective 180 days after publication in the Federal Register, with a compliance date of two years after Federal Register publication. Petitions for reconsideration must be received no later than 45 days after publication.


Click for more FreightWaves articles by John Gallagher.

19 Comments

  1. JuanB

    They need to start giving tickets to four wheelers for the excessive speed they be doing and cutting big rigs off. It’s not our fault if they are not paying attention to their driving.

  2. SILVERA, MBA-PM RONALD E.

    It is called the Mansfield Bar yet the article never mentioned that. How could you forget about poor Jane and how she ended up going under a truck trailer and give both her name and life to the bar.

  3. RM

    Definitely sounds like the safety advocates instead of pushing for removal of distracting technology from the car or pickup truck version of vehicles. They’re trying to add more weight and stupidity to the big rigs and their vehicles. That does not sound conducive to safety to me

  4. Sal

    The burden should be put on the stupid people on the 4 wheelers, o know that when someone rear ends another vehicle that person is cited for following too close, and they are 100> at fault, just as I’d a truck tear ends a car or another truck. 5 years ago, here in CY, a truck was traveling on I84, with his four way flashers on, going 15 mph trying to get onto the shoulder. A CT State Teooper entered the highway traveling at 85 mph on the on ramp no lights no siren, and using the cruisers laptop, got that first hand as a former LEO, hit the back of the trailer, he never even brakes cause he was looking at laptop screen, no skid marks, slammed into ICC bumper and got decapitated. It is the operator of the vehicle behind an 18 wheeler to pay attention to what’s in front of them. Like what was stated above earlier, fine the operator of the cars $1000 just for the damage, they are 100% at fault.

  5. Calvin

    Because it’s our duty to make sure idoit driver make it home at night. Give us a break! It’s not our fault the general public can’t drive. Yet the duty is constantly ours to protect them from themselves. Ridiculous, how about we allow natural selection take it course and call it a day. They’ll breed more ignorant road hazards in the future anyway. Love me or hate me you know I’m right.

  6. J Hughs

    Maybe they need be More Focused on working to make Drivers pay More Attention to their driving and the collision’s with large CMV Wouldn’t be on the rise… And Specking from experience the safty bumpers we have now work very well .I drive a truck and was Hit be a car where the driver WasNot paying attention( on his phone) at an estimated speed difference of 50mph an it didnt doa thing to th icc bumper . He bounced off of it .totaled his car .

  7. Scott Campbell

    I have a great idea. Instead of making the trucking companies responsible for this insanity, charge every car that rear-ended a truck, a $1000 fee to cover the damages to the truck. This is the same government who wants to punish legal gun owners for the criminal actions of demoCRAPs and mooslimes.

    1. Larry Huff

      So instead of going under ,or pushing in the standard D.O.T bumper your saying it’s better to hit a steel wall,I think Nascar should would be better to inform you you are wrong .

      1. Jesus Mejia

        That’s the same logic behind gun control. Nevermind the fact that tailgating, which is the main cause, is a traffic violation. Or nevermind that this a result of split speed limit laws. Or nevermind the mentality of the average four-wheeler that they will be able to sue someone because of all the advertising of the ambulance chasing lawyers out there.

Comments are closed.

John Gallagher

Based in Washington, D.C., John specializes in regulation and legislation affecting all sectors of freight transportation. He has covered rail, trucking and maritime issues since 1993 for a variety of publications based in the U.S. and the U.K. John began business reporting in 1993 at Broadcasting & Cable Magazine. He graduated from Florida State University majoring in English and business.